الواجب والفرض لهما معنى واحد، لأنهما لفظان مترادفان.

Al-Waajib and Al-Fard hold one meaning as they are synonyms (Lafzhaan Mutaraadifaan).

أَمَّا مَا قَالَهُ بَعْضُ الْمُجْتَهِدِينَ، وَمِنْهُمُ الْأَحْنَافُ، مِنْ أَنَّ الْفَرْضَ مَا ثَبَتَ بِدَلِيلٍ قَطْعِيٍّ، وَأَنَّ الْوَاجِبَ مَا ثَبَتَ بِدَلِيلٍ ظَنِّيٍّ، فَلَيْسَ فِي اللُّغَةِ وَلَا فِي الشَّرْعِ مَا يَدُلُّ عَلَى هَذَا التَّفْرِيقِ بَيْنَهُمَا وَيُرْشِدُ إِلَيْهِ.

As for what some of the Mujtahideen have said including the Ahnaaf in respect to the Fard being that which has been established by a Daleel Qat’iy (definite evidence) and the Waajib being established by a Daleel Zhanniy (indefinite evidence), then there is nothing within the language or the Shar’a that indicates and guides to making such a differentiation between them.

الحقيقة في هذه المسألة أنها ما طلبه الشارع طلباً جازماً، ولا فرق في ذلك بين أن يكون الطلب ثابتاً بدليلٍ قطعيّ أو دليلٍ ظنيّ.

The reality of this matter is that it is that which the Shaari’ has requested by a decisive request and there is no difference in respect to whether the Talab (request) was established by a Daleel Qat’iy or a Daleel Zhanniy.