1"Bhikkhus, suppose there were a pool of water that was cloudy, turbid, and muddy. Then a man with good sight standing on the bank could not see shells, gravel and pebbles, and shoals of fish swimming about and resting. For what reason? Because the water is cloudy. So too, it is impossible for a bhikkhu with a cloudy mind to know his own good, the good of others, or the good of both, or to realize a superhuman distinction in knowledge and vision worthy of the noble ones. For what reason? Because his mind is cloudy." [n.43] Mp: "Cloudy (āvilena): enveloped by the five hindrances." At AN5.193 cloudy water is specifically identified with doubt and limpid water with freedom from doubt.

1"Seyyathāpi, bhikkhave, udakarahado āvilo luḷito kalalībhūto tattha cakkhumā puriso tīre ṭhito na passeyya sippisambukampi sakkharakaṭhalampi macchagumbampi carantampi tiṭṭhantampi. Taṁ kissa hetu? Āvilattā, bhikkhave, udakassa. Evamevaṁ kho, bhikkhave, so vata bhikkhu āvilena cittena attatthaṁ vā ñassati paratthaṁ vā ñassati ubhayatthaṁ vā ñassati uttariṁ vā manussadhammā alamariyañāṇadassanavisesaṁ sacchikarissatīti netaṁ ṭhānaṁ vijjati. Taṁ kissa hetu? Āvilattā, bhikkhave, cittassā"ti.

Pañcamaṁ.