During the crucial moments of planning his escape, David points out the practical and emotional weak points of the strategy to Jonathan. He raises a twofold question to figure out exactly how they will communicate and how they will interpret Saul's true intentions.
The first issue is the practical problem of passing the message. David wonders how Jonathan will manage to get the information to him while he remains hidden [רש״י, ביאור שטיינזלץ]. He is especially concerned about who will actually deliver the news, knowing that using a messenger could easily expose their secret [מצודת דוד, מלבי״ם].
Beyond the logistics of delivery, David asks about the message itself, wanting to know who will tell him whether Saul's response is favorable or harsh [מצודת דוד, רד״ק, אברבנאל]. The primary approach among commentators is that David needs to hear the exact details of Saul's reaction. By understanding the specific tone and severity of the answer, David can analyze Saul's true motives for himself. This will allow him to plan his next steps carefully, helping him figure out if Saul simply wants to drive him away or if he actually intends to kill him [רלב״ג, רד״ק, אלשיך].
From another perspective, David is trying to clarify what Jonathan himself considers a harsh answer. Jonathan might only see a real danger if his father explicitly sentences David to death. David, however, understands that even mild or hidden anger is a serious threat that requires an immediate escape [מלבי״ם].
Alongside these practical concerns, David's words are also a cry of pain. Rather than just asking a logistical question, he is expressing deep sadness and anxiety. He is painfully aware that Jonathan is about to suffer scolding, disgrace, and harsh words from his father entirely because of him [אברבנאל].