Here are few teachings on Death from the Bhagavad Gita
Indeed, certain is death for the born, and certain is birth for the dead; therefore, over the inevitable, you should not grieve. (2.27)
Better is one's own ‘duty’, though devoid of merit, than the 'duty' of another well discharged. Better is death in one's own ‘duty’; the 'duty' of another is fraught with fear (is productive of positive danger) . (3.35)
He who is able, while still here (in this world) to withstand, before the liberation from the body (death) , the impulse born out of desire and anger, he is a YOGIN , he is a happy man. (5.23)
And whosoever, leaving the body, goes forth remembering Me alone, at the time of his death, he attains My being; there is no doubt about this. (8.5)
And I am all-devouring Death (10.34)
If the embodied one meets with death when SATTWA is predominant, then he attains to the spotless worlds of the "Knowers of the Highest.” (14.14)
Meeting death in RAJAS, he is born among those attached to action; and dying in TAMAS, he is born in the womb of the senseless. (14.15)