John Gill

Now Hannah, she spake in her heart,.... It was mental prayer she used, some ejaculations of her mind she sent up to God, which she was sensible were well known to him, and she needed not to express vocally: only her lips moved; as her heart spoke, and sent up her petitions, as if she had used words and phrases in form: but her voice was not heard: that she might not seem to be ostentatious in her prayer, and that she might not interrupt others in their devotions; and she knew that her voice was not necessary with respect to God: therefore Eli thought she had been drunken; by the motions she made, and gestures she used, as if she was muttering something to herself, and by her long continuance therein, and it being after a feast she had been at with her husband, and the rest of the family; from all which Eli concluded this must be her case.