Undoubtedly, the most challenging position to have ever been held by a human was the position of Nubuwwah. Along with bearing the excessive weight of revelation, the Prophets AS were faced with many challenges from those who opposed them. Thus, the Beloved Messenger of Allah ﷺ said:

وَعَنْ سَعْدٍ قَالَ: سُئِلَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: أَيُّ النَّاسِ أَشَدُّ بَلَاءً؟ قَالَ: الْأَنْبِيَاء ثمَّ الْمثل فَالْأَمْثَلُ
“The people who undergo the severest trials are the Prophets, followed by the best after them, and then those who are next best.” [Tirmidhi, Ibn Majah and Darimi]

From the galaxy of the Prophets, the paragon of Allah’s creation, Sayyidina Muhammad ﷺ underwent the most difficulties in the path of Allah.

We are told in a hadith:
ما اوذى احد ما اوذيت فى الله
No one was put through difficulty to the extent to which I was put through difficulty in (the path of) Allah. [Hilyat al Awliya’]
It is common knowledge that a person to whom daunting tasks are assigned, needs all the help, support and backing from fellow humans, especially from those who make up his inner circle. How often do we not hear that so and so (the father, wife, etc.) was the secret behind a certain hero’s success? Therefore, it makes perfect sense that a Nabi, especially the one who was about to undergo the greatest difficulty, was in need of a figure of support in his life. Allah, in His infinite wisdom, selected for this task none other than the Mother of the Faithful Sayyidah Khadijah bint Khuwaylid RA.

Hadhrat Khadijah RA enjoys a very lofty rank and position and she enjoys such statuses which no other women could ever achieve. We will thus focus on some of her great merits.

The Prophet ﷺ declared her to be from amongst the best of women.
سَمِعْتُ عَبْدَ اللَّهِ بْنَ جَعْفَرٍ عَنْ عَلِيٍّ ـ رضى الله عنهم ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏ “‏ خَيْرُ نِسَائِهَا مَرْيَمُ، وَخَيْرُ نِسَائِهَا خَدِيجَةُ ‏”
Narrated `Ali RA: The Prophet ﷺ said, “The best of the world’s women is Mariam (at her lifetime), and the best of the world’s women is Khadija (at her lifetime). [Bukhari 3815]

The Prophet of Allah ﷺ also famously said:
نْ أَنَسٍ، رضى الله عنه أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ‏ حَسْبُكَ مِنْ نِسَاءِ الْعَالَمِينَ مَرْيَمُ ابْنَةُ عِمْرَانَ وَخَدِيجَةُ بِنْتُ خُوَيْلِدٍ وَفَاطِمَةُ بِنْتُ مُحَمَّدٍ وَآسِيَةُ امْرَأَةُ فِرْعَوْنَ ‏
Narrated Anas RA: the Prophet ﷺ said: “Sufficient for you among the women of mankind are Mariam bint ‘Imran, Khadijah bint Khuwailid, Fatimah bint Muhammad and Asiyah the wife of Fir’awn.” [Tirmidhi 3878]

Rasulullah ﷺ did not Re-Marry as Long as She was Alive

Aisha RA relates:
لم يتزوج النبى صلى الله عليه و سلم على خديجة حتى ماتت
Rasulullah ﷺ did not take a second wife with Khadijah as long as she was alive. [Sahih Muslim]

Another great virtue of Khadijah RA has been mentioned in Zad al Ma’ad. Rasulullah ﷺ did not marry a second wife in the lifetime of Khadijah RA until she passed away. [Zad al Ma’ad by Ibn Qayyim vol. 1 pg. 26]

This is a great proof of her sublimeness and a sign of the lofty status she enjoined in the sight of Rasulullah ﷺ.