To reserve judgement

To reserve judgement - to delay the process of judging someone or giving one's opinion.

Example - "She said she would reserve judgment on that until next week"

Image - http://cdn.someecards.com/someecards/usercards/i-have-realised-i-am-guilty-of-judging-people-to-quickly-from-now-on-ill-reserve-judgement-till-i-get-to-know-them-better-and-realise-they-are-not-as-nice-as-i-thought-398b1.png