John Trapp on Psalms 16:3

Verſ. 3. Best to the Saints] The family of faith were, by a ſpeciality, the object of Davids bounty. Socrates ſeeing a certain man giving alms to all hee met, were they good or bad, ſaid, male pere as qui ex Gratiis cum ſint Virgines, facias ſcorta. David, the better to perſwade with God to preſerve him ſafe to the Kingdome, promiſeth two things; firſt, that he will cheriſh and countenance the godly party; ſecondly, that he will caſhier and caſt out all kind of Idolatry, and maintain to his utmoſt the ſincere ſervice of God. verſ. 4.

And to the excellent] Or, Noble, glorious, wonderfull, magnificent. The Saints are Princes in all lands, Pſal. 45.16. of an excellent Spirit, Prov. 17.27. More excellent than their Neighbours, dwell they whereſoever, Prov. 12.26. They are ſtiled the glory, Iſa. 4.5. a Crown of glory, Iſa. 62.3. a royall Diadem ibid. a Kingdome of Prieſts, Exod. 19.6. higher than the Kings of the earth, Pſal. 89.27. greater than the four famous Monarchies, Dan. 7.18. worthies of whom the World is not worthy, Heb. 11.38. fitter to be ſet as ſtars in Heaven. And ſurely as ſtars though ſeen ſometimes in a puddle, or ſtinking ditch, though they reflect there, yet have they their ſituation in Heaven. So the Saints, though here in a low condition, yet are they fixed in the Region of happineſſe.

In whom is all my delight] Heb. Cheptſibam; So the Church is called Gods Cheptſibah, Iſa. 62.5. Next to communion with God, the communion of Saints is moſt delectable. It is the very being bound up in the bundle of life, which was the bleſſing of Abigail upon David. Ipſe aſpectus viri boni delectat, ſaith Senecae, the very ſight of a good man (morally good) delighteth; what then of a Saint, Ezra. 10.3? This the Heathen Perſecutors knew, and therefore baniſhed and confined the Chriſtians to Iſles and Mines, where they could not one come at another, as Cyprian obſerveth.