When is the disagreement among scholars considered a mercy, and when is it not so, and what are the areas of this disagreement?

The phrase "disagreement among scholars is a mercy" is understood to mean disagreement in matters of ijtihad (independent reasoning) for which there is no definitive text, or where the evidence is ambiguous. This provides flexibility for the followers to adopt one of the opinions. This type of disagreement may be a test from God to elevate the ranks of the people of knowledge. As for blameworthy disagreement, it is detailed in other fatwas.