A braita extrapolates the verse in Devarim 24:15 that holding back salary is considered like taking away his/her soul. Whose soul - the worker or the employer? Rav Chisda and Rav Huna each bring different answers and explanations, based on verses in Proverbs. From the word "with you" in Vayikra 19:13, they derive three cases where the prohibition to delay salary does not apply. One exception is if the employer passed over the responsibility to pay to a store owner or money changer. If the store owner does not pay the worker, can the worker demand payment from the employer or is the employer no longer responsible? Rav Sheshet and Raba disagree on this issue. Does the prohibition of delaying payment also apply to a contracted worker (kablan) - one who gets paid for the job and not per hour? This depends on a different debate about whether a contracted worker assumes ownership of the item they are fixing or not. If there is a disagreement between the employer and the worker about whether the worker was paid, if it was before the expected day or payment, the worker takes an oath that he/she did not get paid and collects their salary. This goes against the general principle that the oath is usually for one to be exempt from payment (maintain the status quo). Why is this case an exception to that rule? Is there a reason to protect the worker more than the employer?  Various arguments are brought and rejected as the issue is complex. The conclusion is that an employer is busy with work/worker and does not remember whether or not the worker was paid.