Adam Clarke's Commentary on the Bible - Psalms 71:18
Old and grey-headed - In the ninth verse he mentioned the circumstance of old age; here he repeats it, with the addition of hoary-headedness, which, humanly speaking, was calculated to make a deeper impression in his favor. Though all these things are well known to God, and he needs not our information, yet he is pleased to say, "Come now, and let us reason together." And when his children plead and reason with him, they are acting precisely as he has commanded. read more
Adam Clarke's Commentary on the Bible - Psalms 71:17
Thou hast taught me from my youth - I have had thee for my continual instructor: and thou didst begin to teach me thy fear and love from my tenderest infancy. Those are well taught whom God instructs; and when he teaches, there is no delay in learning. read more