तेषामहं समुद्धर्ता मृत्युसंसारसागरात्। भवामि नचिरात्पार्थ मय्यावेशितचेतसाम् ॥

teṣhām ahaṁ samuddhartā mṛityu-saṁsāra-sāgarāt bhavāmi na chirāt pārtha mayy āveśhita-chetasām

These I speedily lift up from the ocean of death and existence, O Pârtha, their minds being fixed on Me.

In plain words: Krishna says he quickly rescues such people from the endless cycle of death and rebirth, because their minds are fixed on him. Partha is a name for Arjuna.