He spake unto them in the cloudy pillar— This passage is very clear as to Moses and Aaron. But it is not any where expressly said that God spake unto Samuel out of a cloudy pillar; however, Dr. Hammond has observed, that it is probable enough from his history, that he did so: for when Samuel was so signally heard by God at Mizpeh, 1 Samuel 7:9. The Lord heard him; and 1 Samuel 7:10. The Lord thundered with a great thunder; where God's voice and thunder were, questionless, like that in Exodus 19:16 where the clouds are mentioned as well as the thunder; and indeed where thunder is, a cloud must be supposed to be; and so this answering of Samuel with thunder, must be God's speaking to him at this time out of the cloud also.
Related Commentaries of Psalms 99:7
Psalms 99:7
7 He spake unto them in the cloudy pillar: they kept his testimonies, and the ordinance that he gave them.