I presented my supplication - This was telling the truth, and nothing but the truth, but not the whole truth. The king did not wish him to defile his conscience, nor did he propose any thing that was not consistent with the truth.
Matthew Henry
Concise Bible Commentary
Jeremiah was not forward to repeat the warnings, which seemed only to endanger his own life, and to add to the king's guilt, but asked whether he feared to do the will of God. The less men fear God, the more they fear men; often they dare not act according to their own judgments and consciences.
SDA Bible Commentary (limited)
Volume 1-7
26. To Jonathan’s house. See on ch.37:15, 16. The weak king was afraid to have anyone know that he had had an interview with the prophet so he provided a cover-up for this interview.