Theravāda Vinayapiṭaka

Monks’ rules and their analysis

Monks’ Training (Sekhiya) 64

… in Anāthapiṇḍika’s monastery. Now at that time the group of six monks taught dhamma to (someone) on a bed … “…

‘I will not teach dhamma to (someone) on a bed and who is not ill,’ is a training to be observed.”

Dhamma should not be taught to (someone) on a bed (and) who is not ill. Whoever out of disrespect teaches dhamma to (someone) on a bed and even lying on the ground (and) who is not ill, there is an offence of wrong-doing.

There is no offence if it is unintentional … if he is the first wrong-doer.