Upvote:1
What actually happens in the event is that Samuel is shown the brothers of David in turn, and in each case the Lord tells Samuel that this one has not been chosen. Only when David appears does the Lord say "Arise, anoint him, for this is he." (1 Samuel ch16 vv6-13). In other words, Samuel does not even try to pour out the oil until the Lord gives permission.
I strongly suspect, I'm afraid, that your preacher (or the person from whom he learned that detail) was quoting the story from memory and has attached his own interpretation to the concept "The Lord did not let it happen". But perhaps there was a much older writer who has committed this fault.