A blessing in disguise is something that is good but is not initially recognized as being good.
1. Satish was slightly bruised from the fall but his mother realized that in a way it was a blessing in disguise; at least now he would not play such dangerous pranks.
2. The sudden declaration of a holiday was a blessing in disguise as the students got an extra day to study.
3. The shower of rain was a blessing in disguise as it would give some temporary relief from the heat.