When a Muslim brother sneezes, he will say الحمد لله ( Praise be to Allah ) and it is the duty
( Voluntary ) of another Muslim to say يهديكم الله ويصلح بالكم ( Yahdeekum ullahu Wa uslih Balakum )
It means May Allah show you the right path and keep you in right condition. It is one of the Islamic
Etiquette.
استغفر الله means " I ask Allah's forgiveness. ( Asthagfirullah )