المعنى الاصطلاحي :

Testifying the due right of someone over another person based on knowledge and certainty for the sake of Allah, without any diversion, deletion, or addition.

الشرح المختصر :

Establishing testimony is a characteristic of the true believers. It signifies giving a full testimony in equity and justice, i.e. the witness tells the truth without favoring a relative over a non-relative, a rich over a poor, or vice versa, even if it has negative effects on the witness; because Allah is more deserving to be obeyed, and He made all people equal in this regard. Giving a reliable testimony is required in all fields of transactions, acts of worship, and relationships. The testimony should contain the words "I testify" which reflect the aspects of witnessing, taking oath, and immediate reporting. A testimony to be established requires fulfilling three main elements: sincerity, justice and honesty. Benefits of establishing testimony include: 1. Establishing testimony is a sign of one's bravery and strength in religion 2. It is a sort of obedience to Allah's commands, which is a fruit of the certainty. 3. It shows sincerity, impartiality, and disobedience to one's evil desires for the sake of Allah. 4. It contributes to the establishment of justice and repelling injustice. 5. Giving a truthful testimony is part of cooperation in righteousness and piety.