Khettūpama Sutta
At Nāḷandā. Then the headman Asibandhakaputta, a follower of the Nigaṇṭhā, approaches the Blessed One, pays homage, and sits down. He then asks, “If the Blessed One dwells compassionate towards all beings, why does he teach thoroughly to some, and not so thoroughly to others?”
The Buddha then asks if a farmer would sow seeds first to the most productive field, then to a less fertile field, and might not sow seed at all to an infertile field.
The Buddha then explains that the monks are nuns are like the fertile field, the lay-
He teaches the Dhamma in detail to the monks and nuns, in brief to the lay followers, and occasionally to the ascetics and recluses of other sects.
The monks and nuns are like a water-
Asibandhakaputta expresses his approval, and takes refuge, declaring himself to be a lay follower. S.iv.314.