It is narrated from Hazrat Ka'b bin Ujrah (may Allah be pleased with him) that I heard the Noble Prophet (peace and blessings be upon him) say: When any one of you performs ablution and does it well, then leaves with the intention of prayer, he is considered to be in prayer until he finishes the prayer. Therefore, during this time, he should not interlace the fingers of his hands with each other.
Hadith Referenceمسند احمد / أول مسند الكوفيين / 18112
Hadith Gradingحکم دارالسلام:حديث حسن، وهذا إسناد ضعيف لاضطرابه، ولابهام بعض رجاله