And do not weaken in pursuit of the enemy. If you should be suffering - so are they suffering as you are suffering, but you expect from Allah that which they expect not. And Allah is ever Knowing and Wise.
English Transliteration
Wala tahinoo fee ibtighai alqawmi in takoonoo talamoona fainnahum yalamoona kama talamoona watarjoona mina Allahi ma la yarjoona wakana Allahu AAaleeman hakeeman
Tafsir of Verse 104
Faint not in seeking the heathen; if you are suffering, they are also suffering as you are suffering, and you are hoping from God for that for which they cannot hope; God is All-knowing, All-wise.
And slacken not in following up the enemy: If ye are suffering hardships, they are suffering similar hardships; but ye have Hope from Allah, while they have none. And Allah is full of knowledge and wisdom.