The old commentators generally understood this to mean that Elijah had no other food at all, and compared this long fast with that of Moses and that of our Lord (marginal references). But the words do not exclude the notion of the prophet's having obtained such nourishment from roots and fruits as the desert offers to a wanderer, though these alone would not have sustained him.

Forty days and forty nights - So he fasted just the same time as Moses did at Horeb, and as Christ did in the wilderness.

And he arose, and did eat and drink,.... Of what was left of the cake and cruse of water, before provided for him:

and went in the strength of that meat forty days and forty nights unto Horeb the mount of God; for so long he was going to that place, though it might have been gone in three or four days; but he went in byways, and wandered about in the wilderness, as the Israelites did, and that for the space of forty days, as they did near forty years; and all this while he had no other sustenance than what he had taken under the juniper tree, from whence he set out, which must be supernatural; for it is said (t), a man cannot live without food beyond seven days; see Gill on Exodus 24:18 the food either staying in his stomach all this while, or however the nutritive virtue of it, by which he was supported, and held out till he came to Horeb or Sinai; called the mount of the Lord, because here he had appeared to Moses in the bush, and from hence gave the law to the children of Israel. Abarbinel is of opinion that this term of forty days was consumed in his whole journey to Horeb, his stay there, and return to the land of Israel.

(t) Macrob. in Soma Scipion. l. 1. c. 6.

"Then he arose, ate and drank, and went in the strength of that food forty days and forty nights to the mount of God at Horeb." As the angel did not tell him whither he was to go, and Elijah wandered to Horeb in consequence of this strengthening, it appears to have been his intention from the very beginning to go into the desert, and see whether the Lord would still further acknowledge him and his work; so that in the support and strength imparted by the angel he saw an indication that he was to follow the footsteps of the divine grace still farther into the desert, and make a pilgrimage to Horeb, with the hope that there perhaps the Lord would reveal to him His counsel concerning the further guidance of the people of His covenant, as He had formerly done to His servant Moses, and give him the necessary instruction for the continuance of his prophetic service. Horeb is called the mount of God here, as it was proleptically in Exodus 3:1, as the place where the Lord confirmed the covenant, already made with the patriarchs, to their descendants, and adopted the tribes of Israel as His people and made them into a kingdom of God. The distance from Beersheba to Horeb is about 200 miles. Consequently Elijah would not have required forty days to travel there, if the intention of God had been nothing more than to cause him to reach the mountain, or "to help him on his say" (Thenius). But in the strength of the food provided by the angel Elijah was not only to perform the journey to Horeb, but to wander in the desert for forty days and forty nights, i.e., forty whole days, as Moses had formerly wandered with all Israel for forty years; that he might know that the Lord was still the same God who had nourished and sustained His whole nation in the desert with manna from heaven for forty years. And just as the forty years' sojourn in the desert had been to Moses a time for the trial of faith and for exercise in humility and meekness (Numbers 12:3), so was the strength of Elijah's faith to be tried by the forty days' wandering in the same desert, and to be purified from all carnal zeal for the further fulfilment of His calling, in accordance with the divine will. What follows shows very clearly that this was the object of the divine guidance of Elijah (cf. Hengstenberg, Diss. on the Pentateuch, vol. i. 171,172).

And he arose, and did eat and drink, and went in the strength of that meat forty days and forty nights unto Horeb the mount of God.

19:8 And went - He wandered hither and thither for forty days, 'till at last he came to Horeb, which in the direct road was not above three or four days journey. Thither the spirit of the Lord led him, probably beyond his own intention, that he might have communion with God, in the same place that Moses had.

19:1-8 Jezebel sent Elijah a threatening message. Carnal hearts are hardened and enraged against God, by that which should convince and conquer them. Great faith is not always alike strong. He might be serviceable to Israel at this time, and had all reason to depend upon God's protection, while doing God's work; yet he flees. His was not the deliberate desire of grace, as Paul's, to depart and be with Christ. God thus left Elijah to himself, to show that when he was bold and strong, it was in the Lord, and the power of his might; but of himself he was no better than his fathers. God knows what he designs us for, though we do not, what services, what trials, and he will take care that we are furnished with grace sufficient.