This is as I heard. Those days, the Buddha was living in the kingdom of the Sakyans, in the city of Kapilavatthu, in the Nigrodha Monastery. One day, Mahānāma of the Sakya clan went to the Buddha, bowed respectfully, sat down to one side, and asked him, “Bhante, this Kapilavatthu city is very prosperous and full of people, with overcrowded streets. Some days, in the late afternoon, after learning the Dhamma from the Buddha or a monk, I enter Kapilavatthu city. There, I come across a stray elephant, stray horse, speedy chariot, speedy cart, or a busy person. Bhante, at that time I lose mindfulness regarding the Buddha, the Dhamma, and the Saṅgha. Bhante, I think: ‘If I were to die at this time, where would I be reborn?’”
“Do not fear, Mahānāma, do not fear! Your death will not bring you misfortune; your passing will not bring you misfortune. When a noble disciple has four factors, he slants towards Nibbāna, slopes towards Nibbāna and inclines towards Nibbāna. What four factors? It’s when a noble disciple has unshakable confidence in the Buddha… the Dhamma… the Saṅgha… And he has virtue loved by the noble ones… leading to concentration.
“Suppose there was a tree that slants to the east, slopes to the east, and inclines to the east. If it was cut off at the root, where would it fall?”
“Bhante, it would fall in the direction that it slants, slopes, and inclines.”
“Mahānāma, in the same way, when a noble disciple has those four factors, he slants towards Nibbāna, slopes towards Nibbāna and inclines towards Nibbāna.”
