Does sin or doubt fall upon a quality controller working in a meat factory who modifies the expiry dates of meat for the benefit of another company, knowing that this job is not his primary source of income?

It is not permissible to alter the expiry date of meat, as this involves deception, harming consumers, and betraying a trust. Allah, the Almighty, says: "O you who have believed, do not betray Allah and the Messenger or betray your trusts while you know [the consequence]." The Messenger of Allah, peace and blessings be upon him, said: "There should be neither harm nor reciprocating harm," and "Whoever deceives is not of us." The quality controller's job is to prevent this, and it is not permissible for him to participate in sin or assist in it, for Allah, the Almighty, says: "And cooperate not in sin and aggression." Assisting in acts of disobedience to Allah burdens the helper with a sin and burden like that of the perpetrator. The Prophet, peace and blessings be upon him, cursed whoever assisted in drinking alcohol.