Visuddhimagga III-28

Yo panāyaṃ lokiyo, so vuttanayena sīlāni visodhetvā suparisuddhe sīle patiṭṭhitena yvāssa dasasu palibodhesu palibodho atthi, taṃ upacchinditvā kammaṭṭhānadāyakaṃ kalyāṇamittaṃ upasaṅkamitvā attano cariyānukūlaṃ cattālīsāya kammaṭṭhānesu aññataraṃ kammaṭṭhānaṃ gahetvā samādhibhāvanāya ananurūpaṃ vihāraṃ pahāya anurūpe vihāre viharantena khuddakapalibodhupacchedaṃ katvā sabbaṃ bhāvanāvidhānaṃ aparihāpentena bhāvetabboti ayamettha saṅkhepo.

次说「世间」（定）：即以前述的方法而净戒及已住立于遍净戒中的（比丘），（一）破除那十种障碍之中的障碍，（二）亲近教授业处的善友，（三）顺适于自己的性行，（四）于四十业处之中执取何种的业处，（五）舍离不适合修定的精舍而住于适合的精舍，（六）破除细障，（七）不离一切修习法而修习。这是略说（世间定的修习法）。

Ñ(III,28): But mundane concentration should be developed by one who has taken his stand on virtue that is quite purified in the way already stated. He should sever any of the ten impediments that he may have. He should then approach the good friend, the giver of a meditation subject, and he should apprehend from among the forty meditation subjects one that suits his own temperament. After that he should avoid a monastery unfavourable to the development of concentration and go to live in one that is favourable. Then he should sever the lesser impediments and not overlook any of the directions for development. This is in brief.

Sayādaw U Sīlānanda: [approach the good friend = find a teacher].; [apprehend from among the forty meditation subjects = take a meditation subject]. Han: Mahāsī Sayādaw: [approach a good friend] and [take a meditation subject].