John Gill Commentary 1 Samuel 3:10

"And Jehovah came, and stood, and called as at other times, Samuel, Samuel. Then Samuel said, Speak; for thy servant heareth." — 1 Samuel 3:10 (ASV)

And the Lord came, and stood
At the place where Samuel lay; either there was, as Kimchi, a form before his eyes in the vision of prophecy, some visible corporeal shape assumed; or a bright splendour an illustrious appearance of the glory of God; or it may be rather the voice, which before seemed to be at some distance where Eli lay; it now seemed nearer, and was as the voice of one just by him, that sounded in his ears:

and called as at other times, Samuel, Samuel :
repeating his name, in order the more to excite his attention:

then Samuel answered, speak, for your servant hears ;
he leaves out the word Lord, which Eli told him to use; for he might be afraid as yet to make mention of the name of the Lord in the vision of prophecy, as Kimchi speaks; or lest it should be the voice of another, as Jarchi; as yet he might not be quite certain whether it was the voice of the Lord, or the voice of a man;

for that he should have any mistrust of its being the voice of a demon or spectre, there is no reason to believe.