Sforno on Genesis
השלום? is he well (healthy) in body? Physical health consists of opposite forces in the body being in perfect balance with one another. [hence the word שלום, “being at peace, being in perfect harmony,” is an acceptable word for describing physical health. Ed.]
Or HaChaim on Genesis
וישאל להם לשלום. He asked them how they were, etc. Joseph first enquired how the brothers were before he enquired after their father's wellbeing. One first greets the people present before enquiring after those who are not present.