Hard and fast( বাঁধা ধরা ) There is no such hard and fast rule in this matter.
In the mean time( ইতিমধ্যে ) Lila will come here to-night. In the mean time you should get her room ready.
A blessing in disguise( বিপরীতে হিত ; প্রথমে খারাপ হিসেবে মনে হলেও পরবর্তীতে ভালো হয় ) Sam's motorcycle accident was a blessing in disguise because he got enough insurance money.
Carry the day( জয়লাভ করা ) Rajib, the best player of the school, carried the day in the annual sports.
slap on the wrist( মৃদু শাস্তি ) Although he broke the rules, he was only given a slap on the wrist
At the eleventh hour( শেষ মুহূর্তে ) The doctor came to the patient at the eleventh hour.