The word(s) "heavy" appears 18 time(s) in 17 verse(s) in Quran in Mohsin Khan translation.

(11) It is He Who shows you the lightning, as a fear (for travellers) and as a hope (for those who wait for rain). And it is He Who brings up (or originates) the clouds, heavy (with water).

(12) "When your sister went and said: 'Shall I show you one who will nurse him?' So We restored you to your mother, that she might cool her eyes and she should not grieve. Then you did kill a man, but We saved you from great distress and tried you with a heavy trial. Then you stayed a number of years with the people of Madyan (Midian). Then you came here according to the fixed term which I ordained (for you), O Musa (Moses)!

(13) Whoever turns away from it (this Qur'an - i.e. does not believe in it, nor acts on its orders), verily, they will bear a heavy burden (of sins) on the Day of Resurrection,

(14) Then, those whose scales (of good deeds) are heavy, they are the successful.

(15) And (the clouds) that bear heavy weight of water.

(16) Verily, these (disbelievers) love the present life of this world, and put behind them a heavy Day (that will be hard).

(17) Then as for him whose balance (of good deeds) will be heavy,