Out of the six Kalimas, Kalime Tayyab is the first kalima. These kalimas are considerably tutored by Muslims to their children around the world.
The first Kalima means the word of chastity. The alternate kalima means shahadah. Third, Fourth Kalima, and fifth kalima's are the remembrance or azkaar of Almighty Allah ( SWT).
The meaning of La ilaha illallah Muhammadur Rasulullah is,
“There is none worthy of worship except God (Allah) and Muhammad is the messenger of God.”
The immense benefit of this kalima can be understood by the following hadith:
Abu Sa’eed al-Khudri quoted Prophet Mohammad (PBUH) as saying that Musa (Alayhi salam) said: “O Lord! Teach me something that I can remember You with and I can supplicate You with. Allah said: “Say ‘La ilaha ill Allah’, O Musa.” He (Musa) said: All of your servants say this. He (Allah) said: “If the seven Heavens and those who dwell in them other than Me and the seven Earths are put into one pan (of the scale) and ‘La ilaha ill Allah’ is put into the other; ‘La ilaha ill Allah’ would be heavier.” (narrated by Jabir bin `Abdullah)
It is quoted in the Quran, “So know (O Mohammad) that La Ilaha IllAllah (none has the right to be worshipped but Allah).” (47:19)
Benefits of Kalima Tayyab:
Tauheed
Tauheed is the Rooh or Soul of Islam. Allah has created this universe for Tauheed.
“I have only created Jinns and men, that they may serve Me.” – Surah Zarriyat Ayah 56
Completion of Deen
Islam was started by Hazrat Adam (A.S) and completed by Prophet Muhammad (SAWS) who is the last Messenger of Allah SWT. In the Holy Qur’an, Allah Almighty says: Oh, Muhammad (SAWS), “This day have I perfected and fulfilled your religion for you, completed my favor upon you and I have chosen for you Islam as your one and Only Religion.” (Quran, 5:3)
“If anyone wishes to have a religion other than Islam, never will it be accepted by him.” – (Quran, 3:85).
Introduction to Unseen Creator
This Kalima makes us swear the actuality of an unseen creator. It introduces us to the Alam of Gaib. Believing in His Unseen important actuality and submitting to Him is possible only by attesting this Kalima through tongue and heart.
Tawakkal on Allah
The First Kalima gives us the confidence and strong belief that we can achieve anything if we misbehave to its norms. Whatever we do should 0nly be for the Sake of Allah. There's nothing more important than Him. Whatever we achieve is only from Him and whatever losses we bear are due to our own short appearances.
It makes us free of condemning and Complaining about our failures. It opens the doors of tone check or Muhaseba. Non-judgemental analysis of our conduct will only help us progress in our diurnal pretensions inshaAllah.
Heavy on Scale
There are so numerous benefits of its enumeration. This Kalima is veritably heavy on the scale. The scale where our conduct will be counted soon. On the Day of Judgement where our focus will be only the appraisal from Allah. The severe corrections will be in front of the eyes. The horrifying realities will be bared and every single action will count for our success on that day.
Allah SWT emphasises on doing Zikr in Cornucopia( Zikran Kaseerah). So we shouldn't miss the occasion to keep our lingo wet with His Zikr.