John Gill Commentary 1 Samuel 20:10

"Then said David to Jonathan, Who shall tell me if perchance thy father answer thee roughly?" — 1 Samuel 20:10 (ASV)

Then said David to Jonathan, who shall tell me ?
&c.] The disposition of Saul's mind towards him, whether he gave a kind answer to the report of Jonathan concerning him:

or what [if] your father answer you roughly ?
or hard words, as the Targum, whether he answers in a kind, loving, and smooth manner, or whether in a rough and angry one: the question is here, how he should be informed of this, since especially, if in the latter, it would not be safe for Jonathan to come himself to him, nor could he well trust the message with any other. Abarbinel thinks, that the first of these expressions is by way of question, who should declare to him his father's will and intention, whether good or bad: and the latter by way of outcry, woe unto me, if your father should answer you roughly; I greatly fear he will chide you for my sake; my heart will be filled with sorrow if you should suffer reproach and rebuke on my account.