See this subject explained in the notes at Matthew 22:37-40.

Thou shalt love the Lord - See this important subject explained at large, on Matthew 22:37-40 (note).

Thy neighbor as thyself - See the nature of self-love explained, on Matthew 19:19 (note).

And he answering said, thou shalt love the Lord thy God,.... This was part of their phylacteries, which they recited every day; See Gill on Matthew 22:37, Matthew 22:39, Mark 12:28, Mark 12:29

Thou shalt love, etc

See on Mark 12:30. Luke adds strength.

And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself.

10:27 Thou shalt love the Lord. The lawyer answered well and gave the sum of the whole law. See De 6:4-5 Le 19:18.

10:27 Thou shalt love the Lord thy God - That is, thou shalt unite all the faculties of thy soul to render him the most intelligent and sincere, the most affectionate and resolute service. We may safely rest in this general sense of these important words, if we are not able to fix the particular meaning of every single word. If we desire to do this, perhaps the heart, which is a general expression, may be explained by the three following, With all thy soul, with the warmest affection, with all thy strength, the most vigorous efforts of thy will, and with all thy mind or understanding, in the most wise and reasonable manner thou canst; thy understanding guiding thy will and affections. De 6:5; Lev 19:18.

27. Thou shalt, &c.-the answer Christ Himself gave to another lawyer. (See on [1631]Mr 12:29-33).

10:25-37 If we speak of eternal life, and the way to it, in a careless manner, we take the name of God in vain. No one will ever love God and his neighbour with any measure of pure, spiritual love, who is not made a partaker of converting grace. But the proud heart of man strives hard against these convictions. Christ gave an instance of a poor Jew in distress, relieved by a good Samaritan. This poor man fell among thieves, who left him about to die of his wounds. He was slighted by those who should have been his friends, and was cared for by a stranger, a Samaritan, of the nation which the Jews most despised and detested, and would have no dealings with. It is lamentable to observe how selfishness governs all ranks; how many excuses men will make to avoid trouble or expense in relieving others. But the true Christian has the law of love written in his heart. The Spirit of Christ dwells in him; Christ's image is renewed in his soul. The parable is a beautiful explanation of the law of loving our neighbour as ourselves, without regard to nation, party, or any other distinction. It also sets forth the kindness and love of God our Saviour toward sinful, miserable men. We were like this poor, distressed traveller. Satan, our enemy, has robbed us, and wounded us: such is the mischief sin has done us. The blessed Jesus had compassion on us. The believer considers that Jesus loved him, and gave his life for him, when an enemy and a rebel; and having shown him mercy, he bids him go and do likewise. It is the duty of us all , in our places, and according to our ability, to succour, help, and relieve all that are in distress and necessity.