Rumi's Masnavi - Because when one intellect is joined with another intellect, it prevents evil action and evil speech;

Because when one intellect is joined with another intellect, it prevents evil action and evil speech; 20

ز آن که با عقلی چو عقلی جفت شد ** مانع بد فعلی و بد گفت شد

(But) when the fleshly soul is associated with another fleshly soul, the partial (individual) intellect becomes idle and useless.

نفس با نفس دگر چون یار شد ** عقل جزوی عاطل و بی‏کار شد

When because of loneliness you fall into despair, you become (bright as) a sun (if you go) under the shadow (protection) of the friend.

چون ز تنهایی تو نومیدی شوی ** زیر سایه‏ی یار خورشیدی شوی‏

Go, seek at once the friend of God: when you have done so, God is your friend.

رو بجو یار خدایی را تو زود ** چون چنان کردی خدا یار تو بود

He who has fixed his gaze upon seclusion (and made it his object), after all ’tis from the friend (of God) that he has learned that (lesson).

آن که در خلوت نظر بر دوخته ست ** آخر آن را هم ز یار آموخته ست‏

One must seclude one's self from strangers, (but) not from the friend: the fur-coat is for winter, not for spring. 25

خلوت از اغیار باید نه ز یار ** پوستین بهر دی آمد نه بهار

(If) the intellect is paired with another intellect, light increases and the way becomes plain;

عقل با عقل دگر دو تا شود ** نور افزون گشت و ره پیدا شود

(But if) the fleshly soul makes merry with another fleshly soul, darkness increases, the way becomes hidden.

نفس با نفس دگر خندان شود ** ظلمت افزون گشت و ره پنهان شود

The friend is thine eye, O huntsman: keep him pure from (unsoiled by) sticks and straws.

یار چشم تست ای مرد شکار ** از خس و خاشاک او را پاک دار

Beware! Do not make a dust with thy tongue's broom, do not make a present of rubbish to thine eye.

هین به جاروب زبان گردی مکن ** چشم را از خس ره آوردی مکن‏