Charles H. Spurgeon on Psalms 110:3

Thy people shall be willing in the day of thy power, etc. The prophet here notes three things respecting the subjects of the kingdom of the Messiah:

1. Their prompt obedience.

2. Their attire or vesture.

3. Their abundance, or multitude.

This representation admirably agrees with what precedes. He had said that the Messiah should reign in the midst of his enemies, but lest any one should think that he would reign only over enemies, unwilling and opposing, as the devils are made subject to Christ, now he lets us know that he will have a loyal people, and obedient subjects, for else there would be wanting that same glory of which Solomon speaks in Pr 14:28, "In the multitude of people is the king's honour." He affirms also, that he would have his own people, who would recognise, receive, and serve him as King, with true obedience, nor would it be a small company, but like the dew, which waters the face of the whole earth. Rivetus.