One of the validation criteria for accepting one narration over another, writes Abu-Bakr Al-Hamdaani in his book الاعتبار في الناسخ والمنسوخ من الآثار, page 17, is that one evidence is a clear statement while the other is an implication.
He cites the hadeeth that specifies the required Zakah (alms) out of sheep, "Out of every forty sheep one sheep." He says it contradicts the hadeeth, "The pen is lifted concerning three...a boy until he reaches puberty." He says that this latter implies that a boy is not addressed by religious commands and therefore is not required to pay Zakah on his sheep. He argues against that by saying that the boy's guardian is still addressed and therefore Zakah is required.
While his conclusion may be correct, his argument has three problems IMHO:
- This is not preponderance; it's exemption.
- What if the boy doesn't have an adult guardian? He did not address that possibility.
- "The pen has been lifted" means that actions of a boy are not written down in his record of deeds. If the boy does not have an adult guardian and he decides to give Zakah, he will be rewarded by God for doing a good deed, not for obliging a religious requirement. If he decides not to pay Zakah, he will not be punished.
All that being said, the validation criterion that implication is no basis for preponderance is a valid criterion.