Albert Barnes Commentary John 11:28

"And when she had said this, she went away, and called Mary her sister secretly, saying, The Teacher is her, and calleth thee." — John 11:28 (ASV)

She went her way. Jesus probably directed her to go, though the evangelist has not recorded it, for she said to Mary, The Master is calling for you.

Secretly. Privately. So that the others did not hear her. This was done, perhaps, to avoid confusion, or because it was likely that if they knew Jesus was coming, they would have made opposition. Perhaps she doubted whether Jesus desired it to be known that he had come.

The Master has come. This appears to have been the title by which he was known to the family. It means literally, teacher, and was a title which he claimed for himself: One is your Master, even Christ, (Matthew 22:8, 10). The Syriac has it, Our Master.