Then said Jonathan unto David, Whatsoever thy soul desireth, I will even do it for thee.

King James Translators' Notes

Whatsoever...: or, Say what is thy mind and I will do, etc

desireth: Heb. speaketh, or, thinketh

Matthew Henry's Concise Commentary

20:1-10 The trials David met with, prepared him for future advancement. Thus the Lord deals with those whom he prepares unto glory. He does not put them into immediate possession of the kingdom, but leads them to it through much tribulation, which he makes the means of fitting them for it. Let them not murmur at his gracious appointment, nor distrust his care; but let them look forward with joyful expectation to the crown which is laid up for them. Sometimes it appears to us that there is but a step between us and death; at all times it may be so, and we should prepare for the event. But though dangers appear most threatening, we cannot die till the purpose of God concerning us is accomplished; nor till we have served our generation according to his will, if we are believers. Jonathan generously offers David his services. This is true friendship. Thus Christ testifies his love to us, Ask, and it shall be done for you; and we must testify our love to him, by keeping his commandments.