وَٱعْلَمُوٓا۟ أَنَّمَآ أَمْوَٰلُكُمْ وَأَوْلَٰدُكُمْ فِتْنَةٌ وَأَنَّ ٱللَّهَ عِندَهُۥٓ أَجْرٌ عَظِيمٌ
3:187; 64:16.
Important Words:
فتنة (trial) is derived from فتن . They say فتنه i.e. he tried or proved or tested him. So فتنه means, a trial meant to separate the good from the bad. See also 2:103, 192; 4:92 & 5:50,72. Thus فتنة is anything that is a means of purification and advancement for the good and a means of exposure and downfall for the wicked.
Commentary:
As فتنة (trial) is a means of purification, our possessions and our children are called a "trial" because they are a means of our spiritual purification. It is by means of them that we are able to make sacrifices in the cause of religion and humanity. If we have no wealth, we cannot give it away in the service of God or of our fellow-creatures. If we have no children, we will not be in a position to train them as good and pious men for the service of God and mankind. Moreover, if we have no children, we shall be free and shall have no obstacle to overcome; and, therefore, our spending money in the cause of God will, in that case, not give us as much credit as it would do if we spent it while we had children. Thus, both our possessions and our children enable us to make sacrifices in the cause of God and our fellow beings; they are, therefore, a blessing, not a curse. But they may become a curse for the wicked, for whom the love of wealth and children proves a great stumbling block.
The words, a great reward, signify that when God has conferred on us blessings like wealth and children without any endeavour on our part, He can bestow on us far greater rewards, if we strive in His cause and try to win His favour. But if the word فتنة (trial) is taken in a bad sense, i.e. a stumbling block, then the words "a great reward" would signify that if our wealth and children prove a stumbling block for us, we should not allow them to stand in our way, but should turn to God with Whom we will find a great reward for this sacrifice of ours.
7:87; 3:124; 64:16.