(refrain: do Jhāna! Dont’ be heedless!) (SN 43) Iti kho, bhikkhave, So, monks, desitaṃ vo mayā a-saṅkhataṃ, I’ve taught you the un-conditioned (and) desito a-saṅkhata-gāmi-maggo. I’ve taught you the path that leads to the unconditioned. Yaṃ, bhikkhave, satthārā karaṇīyaṃ Monks, (what a) teacher should-do sāvakānaṃ hitesinā anukampakena anukampaṃ upādāya, (for the) disciples, out of compassion, kataṃ vo taṃ mayā. done that I have. Etāni, bhikkhave, rukkha-mūlāni, Here, monks, are tree-roots. etāni suññ'-āgārāni. Here, (are these) empty-huts. Jhāyatha, bhikkhave, (Practice) jhāna, monks! mā pamādattha; Don’t (be) negligent! mā pacchā vippaṭisārino ahuvattha. Don’t later regret it! Ayaṃ vo amhākaṃ anu-sāsanīti. This is my instruction to you.” (there's more references than this, need to figure out the various conjugations for jhaayatha) jhāyatha (13) nijjhāyatha (1) jhāyathānanda (3) DN MN MN 1 , 1. mūlapariyāy...
always question authority