This appears to be a distortion of the Battle of Bodange, May 10th, 1940. The 5th company of the 2nd Battalion of the 1st Regiment of Chasseurs Ardennais (about 120 men) delayed elements of the 1st Panzer Division (not 7th Panzer) on the first day of the Battle of France (and Belgium). 40 men possibly refers to specifically the surrender of the 3rd Stand (Platoon).
I fixed the Wikipedia article.
In World War 2, the Chasseurs Ardennais (Ardennes Hunters) were a division of Belgian bicycle infantry supplemented with a few light tanks. They were assigned to cover the border with Luxembourg and blow up bridges over the Sûre river. They were spread very thin. The 2nd Battalion was based at at Fauvillers about 3km west of the river. 5th Company under Capitaine-Commandant Maurice Bricart defended the crossroads town of Bodange on the Sûre. 4th Company defended Martelange to the southeast.
5th Company consisted of 3 "stands" (platoons). One HQ stand, and two rifle stands. One stand was about 40-50 men.
By 4am on May 10th, 1940 all bridges around Bodange were destroyed.
In the morning, 5th Company received news of German airborne troops between them and Fauvillers. These were part of Operation Niwi to clear a path for the 1st and 2nd Panzer Divisions between Nives and Witry. 5th Company sent their lone T-13 tank destroyer to assist. In a twist of fate, Operation Niwi cut the telephone lines and the 1st Chasseurs Ardennais never received the order to withdraw.
4th Company had withdrawn from Martelange allowing the Germans to cross. 2nd Stand (platoon) of about 15 men and 2 machine guns was deployed forward in Wisembach and found themselves in danger of being surrounded by the approaching Germans. They fell back on bicycle to Bodange. About 1130 the now empty positions at Wisembach were captured. 5th Company was ordered to hold.
Many members of the Chasseurs knew the area quite well and used this knowledge to carefully set up their defenses in sturdy houses with interlocking fields of fire. The Germans first advance was stopped by the combined fire of seven machine guns, but 2nd Stand's position was overrun. The survivors fell back.
About 2pm a group of German motorcycles, three armored cars, and some trucks advanced from Warnach in the north-west. 3rd Stand in the town center under Lieutenant Authpenne held their fire until the motorcycles reached a bend in the road and then opened fire scattering them. They turned their fire on the trucks. Lacking any anti-tank weapons the armored cars were a problem. One fortuitously drove into an anti-tank ditch. The other two, fearing mines, halted. The attack was stopped.
By 3pm ammunition was running low. Capitaine-Commandant Bricart moved forward to see the situation at the front himself but was wounded. His HQ fell back to Traquebois halfway to Fauvillers.
At 4pm 3rd Stand came under artillery fire. Fortunately their stone houses were good protection. They were taking enfilade fire from 2nd Stand's former position on Fieltz hill. Rather than expose themselves in the streets, 3rd Stand resorted to throwing supplies from house to house.
By 5pm the Germans had advanced. 3rd Stand was all but out of ammunition and prepared to withdraw. They fired their last magazines at the advancing Germans and surrendered. The Germans were surprised to find they were fighting a single platoon. 26 Chasseurs were captured in the town.
Bricart and 5th Company, realizing Bodange had fallen, attempted to retreat but was killed by machine gun fire. 11 men killed, 20 wounded. The rest were captured. 1st Panzer's casualties were about 100.
1st Panzer's objective for the day was Neufchateau, 20 km to the west of Bodange. 5th Company had delayed them for a day.
Swedish Military History Heavy Metal Band (yes, they are a thing which exists) Sabaton has a song Resist and Bite (lyric video) about the Chasseurs Ardennais which may have contributed to the confusion.
War is coming swiftly
The border is closing in
We’re a company of soldiers
We’re 40 rifles strong
Fight for 18 days of battles
No odds are on our side
Few will fight for all
Until the bullets are gone
But when captured by the Axis
And forced to tell the truth
We will tell them with a smile
We will surprise them with the laugh
We are all
We were all
We were told to hold the border
And that is what we did
Honoured by our orders
In despite of our foe
I had to do a lot of this from translation. The video was very useful in providing an overview.