How do we reconcile between the following two narrations?
1. If the wife or treasurer spends from the owner’s wealth then both will get equal/full reward [… min ghayri ay yunqasa min ujurihim shayan.]
2. The Hadith in Sahih Muslim as well, where it appears both will share the reward half half in the case where the slave gives sadaqah from his master’s wealth. [... wal ajru bainakuma nisfan.]
There is no contradiction between the two narrations.
It is possible that both parties will be rewarded equally (as in the first narration), and when that total is divided is will naturally result in the two halves being same (as mentioned in the second narration in your question).
See Fathul Bari for more, Hadith: 1441 as well Sharhun Nawawi, Hadith: 2361.
And Allah Ta’ala Knows best,
Answered by: Moulana Muhammad Abasoomar