The general meaning is this: Jonathan had an intuitive sense, doubtless from God, that David would be established on the throne. By God's mercy, he…

And Jonathan said to David, O LORD God of Israel, when I have sounded my father about tomorrow any time, or the third day, and, behold, if ther…

But also you shall not cut off your kindness from my house
for ever
His family should…

Jonathan faithfully promises that he would let David know how he found his father disposed towards him. It will be a kindness to ourselves and to o…