Brihat Samhita
मेघाः स्निग्धाः संहताश्च प्रदक्षिणगतिक्रियाः । तदा स्यान्महती वृष्टिः सर्वसस्य अभिवृद्धये ॥ २२-०८ ॥
When the clouds are smooth, compact, and move in a rightward (auspicious) course, then there will be abundant rainfall, leading to the growth and prosperity of all crops.
english translation
meghAH snigdhAH saMhatAzca pradakSiNagatikriyAH । tadA syAnmahatI vRSTiH sarvasasya abhivRddhaye ॥ 22-08 ॥
hk transliteration by Sanscript